The present invention relates to check valves and, in particular, valves suitable for mounting in a liquid supply line.
Self draining water systems for the supply of water to a dwelling or building are known. Such systems involve pumping water from a source to a destination such as a building by means of a submersible pump or other type of pump. Such systems are often used in areas that are subject to winter conditions where water lines can freeze if exposed. If the water system will be used in such winter conditions, it is important that the water system be set up so that the water line which is subject to freezing conditions will automatically drain whenever the pump stops, thus preventing freeze up. A known drawback of such a water supply system however is that when the water drains from the waterline it does so through the submersible pump. Because of this there is a good possibility that the pump motor will be damaged if the pump starts while water is draining through it. Before the present invention, there was no known method for alleviating this problem.
It is an object of the present invention to provide a check valve that eliminates the aforementioned disadvantage associated with the known self-draining water system. With the use of the present check valve, the draining of the water back through the pump is prevented. It is a further object of the invention to provide a check valve which is simple in its construction and can be manufactured at reasonable cost.